THIS BRANCH CONTAINS A PROPOSAL FOR A LICENSE CHANGE AND IS NOT MEANT FOR RELEASE

Why FFI

DL just doesn't want to work correctly on my x86_64 linux boxes and on
OSX, so here's a refactoring using FFI.

These modifications were partly inspired by Patrick Stenmark's work,
which can be found at github.com/spatrik/gd2-ffi/,
although the goal of these modifications are a complete GD2 Ruby library
using FFI. I've also included the beginning of a test suite, although
coverage isn't quite complete yet.

This GD2 library should “just work” as a replacement for Robert's
original GD2 library, although without a complete test suite and the time
and resources to do complete testing, it is difficult to know for sure.
Reports on successful test runs are welcomed.

Robert's Original Notes

“I wrote this Ruby library because I wasn't satisfied with the existing
Ruby/GD extension library. Among other things, it had no support for
creating images from PNG or JPEG data already in memory.

Ruby/GD2 is 100% Ruby and uses dl to link with the gd shared library. Most
of the gd API is supported in some way, however the interface is quite
different so that we can do things The Ruby Way as much as possible.